"
Fixes#5134, Eviction concurrent with preempted partition entry update after
memtable flush may allow stale data to be populated into cache.
Fixes#5135, Cache reads may miss some writes if schema alter followed by a
read happened concurrently with preempted partition entry update.
Fixes#5127, Cache populating read concurrent with schema alter may use the
wrong schema version to interpret sstable data.
Fixes#5128, Reads of multi-row partitions concurrent with memtable flush may
fail or cause a node crash after schema alter.
"
* tag 'fix-cache-issues-with-schema-alter-and-eviction-v2' of github.com:tgrabiec/scylla:
tests: row_cache: Introduce test_alter_then_preempted_update_then_memtable_read
tests: row_cache_stress_test: Verify all entries are evictable at the end
tests: row_cache_stress_test: Exercise single-partition reads
tests: row_cache_stress_test: Add periodic schema alters
tests: memtable_snapshot_source: Allow changing the schema
tests: simple_schema: Prepare for schema altering
row_cache: Record upgraded schema in memtable entries during update
memtable: Extract memtable_entry::upgrade_schema()
row_cache, mvcc: Prevent locked snapshots from being evicted
row_cache: Make evict() not use invalidate_unwrapped()
mvcc: Introduce partition_snapshot::touch()
row_cache, mvcc: Do not upgrade schema of entries which are being updated
row_cache: Use the correct schema version to populate the partition entry
delegating_reader: Optimize fill_buffer()
row_cache, memtable: Use upgrade_schema()
flat_mutation_reader: Introduce upgrade_schema()